A RF power supply is a device for generating RF power signals, and is a core component of the semiconductor process equipment. All the equipments that generate plasma for processing material need the RF power supply to provide energy. Process manufacturing equipments of integrated circuits, solar cells and LEDs (Light Emitting Diodes), such as etcher, PVD (Physical Vapor Deposition) equipment, PECVD (Plasma Enhanced Chemical Vapor Deposition) equipment, ALD (Atomic layer deposition) equipment and so on are equipped with the RF power supplies with different power specifications.
A RF power supply is generally composed of a RF signal generator, a RF power amplifying circuit, power supplying lines and a RF power detector. Currently, the integrated circuit manufacturing industry develops toward a goal of making a linewidth thinner. In the manufacturing process, the linewidth is changed from 90 nm, 65 nm, 45 nm, to the latest 32 nm. This brings higher requirements to the output power of the RF power supply. That is to say, the fluctuation range of the output power should be small enough. As to the output power control of the RF power supply, it is essential whether the detection of the RF power is accurate.
It is impossible for an existing RF power detector to achieve the consistency of the accuracy of the RF power detection since the detecting circuit of the existing RF power detector has a big dead-band, and a small dynamic range. That is to say, since there are large errors during the detection of small RF power, it is uncertain whether the process equipment can process a wafer with a smaller linewidth. As to the 32 nm manufacturing process, if the existing technology is used, it is impossible to achieve a thin linewidth, and thus an expected pattern, this finally results a failure of the manufacturing process.